A class of self-designing clinical trials is considered which according to an effective but simple, finite learning algorithm consists of automatically adaptively planned weighted group sequential trials with a decision about rejection of the null-hypothesis at each step, but the full...

In a general variance component model with positive variance components a short-cut method is presented that yields almost everywhere for these components positive estimators that are invariant with respect to mean value translation and stay near the unbiasedness.

In combining several tests of significance the individual test statistics are allowed to be dependent. By choosing the weighted inverse normal method for the combination, the dependency of the original test statistics is then characterized by a correlation of the transformed statistics. For this...

Sind in einer statistischen Analyse mehr als eine Variationsursache zu berücksichtigen_ so zerfällt die Gesamtvariation in mehrere Komponenten. Für diese sind in der Regel auch Beziehungen oder Ordnungen bekannt. Aber keine der bekannten Schätztheorien ist in der Lage, diese Ordnungen auch...

In many fields of applications, test statistics are obtained by combining estimates from several experiments, studies or centres of a multicentre trial. The commonly used test procedure to judge the evidence of a common overall effect can result in a considerable overestimation of the...

Research in combining of economic forecasts made by several research institutes on the same economic variable has focused on estimation, hoping that the combined forecast will be improved by taking into account the expert opinions of the institutes. We provide a confidence interval on the...

In this paper we derive asymptotic x 2 - tests for general linear hypotheses on variance components using repeated variance components models. In two examples, the two-way nested classification model and the two-way crossed classification model with interaction, we explicitly investigate the...

Different estimation methods for covariance parameters in meta-analyses can result in conflicting p-values concerning the test of treatment effect. We propose a valid method to overcome this problem at least partially by introducing a new estimator for the standard deviation of the common...

Concerning the actual significance level, we investigate the commonly used combined test procedures of meta-analysis, which contain the choice of the model, in which the analysis is carried out, and the commonly used tests for treatment effect in the fixed and random effects model, and some new...

In many meta-analysis cases the estimator of the overall effect in independent trials or experiments leads to unjustified significant results. This paper considers trials with two arms where the summary statistic of interest is either the mean difference or the risk difference. By using...